Data On Food Antioxidants Aid Research
Filed Under News November 29, 2007
Measures of the antioxidant capacities of 277 selected foods have been released by Agricultural Research Service (ARS) scientists. The new database provides easy access to antioxidant values for a wide variety of foods, many of which may be excellent sources of healthful compounds.
The database will be used by scientists to help guide ongoing research into how antioxidants may correlate to health benefits. For example, many fruits and vegetables are known to be good sources of antioxidant vitamins, such as E, C, and beta carotene, a form of vitamin A. But these natural foods also contain other compounds, collectively known as phytonutrients, that may contribute to health.
The database was prepared by ARS researchers at the Nutrient Data Laboratory, part of the agency’s Beltsville Human Nutrition Research Center (BHNRC) at Beltsville, Md., in collaboration with colleagues at the ARS Arkansas Children’s Nutrition Center in Little Rock. ARS is the U.S. Department of Agriculture’s chief scientific research agency.
Many of the fruits, nuts, vegetables and spices listed were analyzed for their Oxygen Radical Absorbance Capacity, known as ORAC, at the Arkansas center. ORAC is one of a number of methods available to evaluate the antioxidant capacities of foods. The method was developed by ARS chemist Ronald Prior with colleagues. Prior also studies the ability of antioxidants to be absorbed and utilized within the human body.
Data on foods analyzed using the ORAC method were also gathered during an extensive search of peer-reviewed, scientific literature, and screened through a USDA-developed, data-quality-evaluation system. Both the screened data and the analyzed data are listed in the database, along with data quality indicators. Antioxidant capacity measures may vary due to factors such the type of cultivar studied and its growing and harvesting conditions, as well as the methods used for a food sample’s preparation, processing, and/or analysis.
The new release expands upon the 2004 data release by ARS on estimates of the antioxidant capacity of 171 foods.
The new database is available at http://www.ars.usda.gov/nutrientdata/ORAC
Flavonoid-rich Diet Helps Women Decrease Risk Of Ovarian Cancer
Filed Under News November 22, 2007
Research by the Channing Laboratory at Brigham and Women’s Hospital (BWH) reports that frequent consumption of foods containing the flavonoid kaempferol, including nonherbal tea and broccoli, was associated with a reduced risk of ovarian cancer. The researchers also found a decreased risk in women who consumed large amounts of the flavonoid luteolin, which is found in foods such as carrots, peppers, and cabbage.
“This is good news because there are few lifestyle factors known to reduce a woman’s risk of ovarian cancer,” said first author Margaret Gates, a research fellow at BWH. “Although additional research is needed, these findings suggest that consuming a diet rich in flavonoids may be protective.”
Research Shows Astaxanthin can Be Extracted from Prawn Shells
Filed Under News November 22, 2007
A researcher in the University of New South Wales(UNSW) has developed a new technique for extracting a powerful antioxidant from prawn shells.
Astaxanthin, is the pigment which gives cooked prawns their red colour but is almost all contained in the shells and heads thrown away.
Antioxidants are substances that may protect cells from the damage caused by unstable molecules known as free radicals. Free radical damage may lead to cancer. Antioxidants interact with and stabilize free radicals and may prevent some of the damage free radicals otherwise might cause. Examples of antioxidants include beta-carotene, lycopene, vitamins C, E, and A, and other substances.
Astaxanthin has long been recognised as being about 10 times stronger than carotene, the more common antioxidant found in many fruits and vegetables.
The technique evolved by Renuka Karuppuswamy to extract astaxanthin from waste prawn heads and shells is efficient enough to make commercial-scale extraction viable.
Natural antioxidants now required in Soil Association organic fish feeds
Filed Under News November 21, 2007
The Soil Association has met its target of eliminating the use of synthetic antioxidants in its certified organic fish feeds . Only natural antioxidants are now permitted in these feeds and their ingredients.
This is the first time such a requirement has been placed on any sector of the fish farming industry. [1] Four months have now passed since the deadline set by the Soil Association in July 2007, and all those involved in the production of Soil Association-certified organic fish feeds and their ingredients have successfully switched to natural products.
Organic foods and animal feeds aim to avoid all synthetic ingredients, but while the terrestrial organic feed industry has already replaced synthetic antioxidants with natural alternatives, it has been more of a challenge to protect the unique highly unsaturated fats found in fishmeal and fishoil from spoilage by oxidation. [2]
After establishing the availability of potential natural products, [3] the Soil Association set a deadline of 1 July 2007 after which all antioxidants used in organic fish feeds and their raw materials must be of natural origin. By working with fishmeal and oil manufacturers, feed mills and various companies developing natural antioxidant products, the necessary testing and development has taken place and the Soil Association has met its target.
Peter Bridson, Soil Association Aquaculture Programme Manager, said:
“It has been very satisfying to bring all the links of the supply chain together to work on this project. It has required a lot of testing. We agreed the deadline with the stakeholders last year and everyone has worked together to achieve it. By using fishmeal and oil made from the recycled filleting wastes of fish already caught for human consumption, we already have the most sustainable feeds in the industry, and it is great to know that we can also protect their unique omega-3 fatty acids with natural antioxidants.”
[1] The bulk of non-organic fish feeds and their ingredients continue to contain synthetic antioxidants such as BHT (Butylated hydroxytoluene) and BHA (Butylated hydroxyanisole) and Ethoxyquine.
Ethoxyquin has low acute toxicity when administered orally, dermally, or by inhalation. Exposure to ethoxyquin in the workplace has been linked to allergic contact dermatitis, and the substance should be considered as a sensitiser in humans.
Pesticides Safety Directorate, Defra, 1998
[2] The more unsaturated an oil is, the more prone it is to spoilage (rancidity) by oxidation. The exceptional nutritional value of oily fish and their oils is mostly due to the high levels of omega-3 fatty acids DHA and EPA, both of which are highly unsaturated. The aquaculture industry has therefore relied on synthetic antioxidants (particularly ethoxyquin), but effective natural alternatives are now available.
[3] Natural antioxidants typically use extracts of plants, seeds and nuts, and have active ingredients including various forms of vitamin E tocopherols, vitamin C, gallates (from gallnuts) and diterpenes (from rosemary).
Study Shows Organic Food Is Better
Filed Under News November 18, 2007
A study from the University of California-Davis offers more evidence that organically raised vegetables are healthier than those grown under nonorganic practices that rely on chemicals for fertilization and weed, pest and disease control.
Led by professor and food chemist Alyson Mitchell, the study compared levels of two flavonoids — quercetin and kaempferol — in organic and nonorganic tomatoes. Flavonoids are plant compounds thought to have a variety of health-promoting properties, including protection against cancer, dementia and heart disease.
Averaged over 10 years, levels of quercetin were 79 percent higher in the organically grown fruit, and levels of kaempferol were 97 percent higher. “We sort of went into this expecting higher levels,” Mitchell told The New York Times. “We did not expect to find the levels that we found.”
The study also found that flavonoid levels increased over time as organic cultivation methods steadily improved soil quality. Average yields in the organic and nonorganic plots were the same.
New Research Confirms Wild Blueberry Antioxidant Power
Filed Under News November 17, 2007
New research published in the current issue of the Journal of Agricultural and Food Chemistry (55 (22), 8896-8907, 2007) shows that Wild Blueberries have the highest cellular antioxidant activity of selected fruits tested. Lead scientist Rui Hai Liu, Ph.D. used the cellular antioxidant activity (CAA) assay-a new assay developed by the Cornell University Department of Food Science to determine antioxidant activity of antioxidants, foods, and dietary supplements. Wild Blueberries performed better in cells than cranberries, apples, red and green grapes.
According to Dr. Liu, the CAA assay takes antioxidant measurement to a new level moving beyond test tube assays to bioactivity inside cells. “We have taken the next step toward understanding antioxidant activity by examining how antioxidants react with cells. This new approach is more biologically relevant as it accounts for uptake, metabolism, distribution and activity of antioxidant compounds in cells versus solely looking at antioxidant value.” Dr. Liu’s work builds upon current antioxidant research using the chemistry or test tube assays, like Oxygen Radical Absorbance Capacity (ORAC). “ORAC is still a valuable test. What we have done is advance the research to see how these compounds react with cells. We believe this is a stronger measure of how antioxidant compounds could potentially react in the body.”
According to USDA scientist and developer of the ORAC test Ron Prior, Ph.D., the CAA assay is an advancement. “The CAA assay provides information regarding cellular levels of antioxidants which is important to our understanding in this area of antioxidant research. How useful the assay will be in predicting in vivo uptake and availability of dietary antioxidants remains to be determined with further research.”
Wild Blueberries: Nature’s Antioxidant Superfruit
Wild Blueberry Association Nutrition Advisor Susan Davis, M.S., R.D. advises consumers to choose colorful, naturally nutrient-dense foods like Wild Blueberries. “Wild Blueberries are packed with protective natural compounds with antioxidant and anti-inflammatory effects. Eat at least 1/2 cup of Wild Blueberries every day as part of a well-balanced diet. Eating antioxidant- rich foods is key to weight management, reducing risks for chronic diseases and healthy aging.” According to Davis, antioxidants help protect cells against free radicals-unstable oxygen molecules associated with cancer, heart disease, Alzheimer’s and other effects of aging. A serving of Wild Blueberries has more antioxidants than most other fruits. (Journal of Agricultural and Food Chemistry, 52:4026-4037, 2004.)
Davis noted that Wild Blueberries are now available in supermarket freezer cases nationwide. Individually quick-frozen, Wild Blueberries are frozen at the peak of freshness and are just as nutritious as fresh. “It’s easy to incorporate more fruits and vegetables into the family meal plan when you have frozen on-hand,” said Davis. “Just grab a half-cup of frozen Wild Blueberries from the freezer, add them to cereal, make a smoothie or enjoy them as is.”
Davis advises choosing a brightly colored fruits and vegetables which are loaded with health-promoting phytochemicals. Wild Blueberry phytochemicals known as anthocyanins give the fruit its deep blue color and are at work in the body helping fend off environmental assault from poor diet, lack of exercise or other stressors.
Wild Blueberry Association of North America
The Wild Blueberry Association of North America is a trade association of growers and processors of Wild Blueberries from Maine, dedicated to bringing the Wild Blueberry health story and unique Wild Advantages to consumers and the trade worldwide. To learn more about Wild Blueberries visit wildblueberries.com
Source: Wild Blueberry Association of North America
Flavonoids Control Cell Processes
Filed Under News November 12, 2007
Scientists from Dresden proved that plant substances such as those found in red wine, soy, or green tea can accelerate or retard vital processes in cells. These molecules bind to the protein actin which is implicated in cell movement and cell division. According to experimental results published recently in Biophysical Journal the ability of actin to join to long chains is either hindered or improved. Surprisingly, it has been shown that these substances also affect the rate at which genetic information is processed in the cell’s nucleus.
The recent study reports two surprising results that are related to the binding of flavonoids to the protein actin. Actin is one of the best-studied and most abundant proteins. Together with other biomolecules, it enables muscle contraction, changing the cell shape, and separation of daughter cells during cell division. Two years ago, biologists from the Technische Universität Dresden were surprised to find that flavonoids can dock to actin in the nucleus of living cells1.
Now, together with the biophysics group at the Forschungszentrum Dresden-Rossendorf (FZD), they proved in a test tube that flavonoids influence the growth of chains of actin molecules, a process that is linked to the cellular functions of actin2. Flavonoids can strengthen or weaken this process. Astonishingly, the same dependency on flavonoids was observed for the speed at which the genetic material is read from the DNA in the cell nucleus. These results, according to Prof. Herwig O. Gutzeit from the TU Dresden, show that the direct biological effects of flavonoids on actin may also influence the activity of genes in a cell.
The biophysicist Dr. Karim Fahmy from the Forschungszentrum Dresden-Rossendorf (FZD) was able to demonstrate the molecular mechanism by which flavonoids can affect actin functions. The flavonoids function as switches that bind to actin and promote or inhibit its functions.
Using infrared spectroscopy, Fahmy studied the interaction of actin with the activating flavonoid “epigallocatechin” and the inhibitor “quercetin”. This method is well-suited for demonstrating structural changes in large biomolecules without any interventions that may affect the extremely sensitive proteins. Upon addition of the selected flavonoids to actin, the structure of the actin changes in a dramatic and typical way. Depending on the type of flavonoid, the “actin switch” is set to increased or reduced functional activity.
Boston University Medical Center researcher’s abstract selected by Society for Neuroscience
Filed Under News November 9, 2007
Boston, MA—David Farb, PhD, recently had an abstract selected that was highlighted by the Society for Neuroscience (SFN). The abstract details how antioxidants influence dopamine release from striatal synaptosomes. It will be presented at SFN’s 37th annual meeting November 7th in San Diego, California.
Farb is the professor and chairman of the Department of Pharmacology & Experimental Therapeutics at Boston University School of Medicine. He is also the director of the Biomolecular Pharmacology Training Program, the interdepartmental program in biomedical neuroscience, and heads the Laboratory of Molecular Neurobiology.
Farb’s abstract details the relationship between antioxidants and dopamine. Antioxidants can protect the central nervous system from oxidative damage. The level of oxidation and reduction of molecules reflects conditions within the nervous tissue. Increased levels of oxidative damage are believed to be involved in neurodegenerative diseases such as Parkinson’s disease, Alzheimer’s disease and stroke.
In the brain, neurons communicate with each other via synaptic connections in which signals are transmitted by the release of chemical neurotransmitters from presynaptic axon terminals. Farb and fellow BUSM researchers examined the release of a specific neurotransmitter, dopamine, from isolated pre-synaptic axon terminals.
Researchers sought to determine whether the presence of antioxidant compounds could influence spontaneous dopamine release from synaptosomes. They concluded that the release of dopamine could be influenced by numerous factors, including input from other neurotransmitters as well as the reducing/oxidizing state of the cell. Inclusion of the water soluble, sulfhydryl containing antioxidant glutathione, or the glutathione precursor NAC lowered spontaneous dopamine release by 85 percent. The antioxidant vitamin E had no effect on dopamine release.
“Not all antioxidants are equivalent,” said Farb. “Our results suggest that the ability of NAC or glutathione at therapeutic doses to rapidly and reversibly stabilize the release of dopamine raises the possibility that such antioxidants may have significant potential for the treatment of oxidative damage in neurodegenerative diseases.”
Farb chairs the Executive Committee for the Medical Sciences Training Program and is a member of the Bioinformatics Program. He also served as neurosciences consultant for WGBH-Boston PBS affiliate on the NOVA episode, Mirror Neurons and, as a member of the Drug Development Work Group of Mass Insight. He also co-authored the Massachusetts Technology Road Map for Drug Discovery.
Farb has served as a consultant to large and small pharmaceutical companies, intellectual property law and portfolio investment firms. He was a member of the founding Scientific Advisory Boards of CoCensys and DOV Pharmaceuticals and the Scientific Founder of Scion Pharmaceuticals (acquired by Wyeth), which commercialized his patents on high throughput electrophysiology and small molecule modulators of amino acid receptors. Farb currently serves on the SAB of DOV Pharmaceuticals and Helicon Therapeutics (pending). He holds nine issued U.S. patents and one patent issued in Australia.
Farb’s current research is directed toward understanding the mechanisms of action of abused substances and steroid hormones and their interactions with excitatory and inhibitory amino acid receptors in the central nervous system. The research focuses on the mechanism of action and discovery of neuromodulators as therapeutic agents and on the structure, function, and cellular dynamics of ion channels and receptors in the brain and spinal cord. Recently, Farb’s laboratory demonstrated that pregnanolone hemisuccinate inhibits reinstatement of cocaine seeking behavior and this compound has been acquired by NIDA for preclinical development in its Medications Development Program.
With 30,000 or more attendees, the SFN’s annual meeting is the world’s largest and most influential yearly gathering of neuroscientists. In more than 16,000 presentations this year, members will discuss the latest advances in the understanding of the nervous system and its disorders.
ARS launches antioxidant value database
Filed Under News November 7, 2007
The USDA’s Agriculture Research Service has published a new database giving antioxidant values for 277 fruits, nuts, vegetables and spices, which could help inform industry and scientists about healthy potential of certain ingredients.
Antioxidants are belived to prevent cellular damage by preventing the formation of free radicals, atoms that are formed when oxygen interacts with certain molecules. These free radicals can, in turn, damage DNA and pave the way towards serious illness like cancer, other diseases, and signs of aging.
A database that comprehensively lists antioxidant value of foods could therefore prove helpful to companies making health food products, as well as scientists investigating antioxidants’ health benefits.
Although there are several categories of antioxidant, (flavonoids, anthocyanins, polyphenols…), scientists often measure their activity according to their Oxygen Radical Absorbance Capacity, or ORAC value.
This measure was originally devised by an ARS chemist, Ronald Prior and colleagues.
The researchers conducted ORAC tests on a number of the 277 food products at the Arkansas center.
The ARS has previously made public a database made public in 2004, which estimated antioxidant capacity of 171 foods.
How Natural Antioxidants Fight Fat
Filed Under News November 6, 2007
Taiwan Scientists are reporting new insights into why diets rich in fruits and vegetables reduce the risk of obesity. Their study focuses on healthful natural antioxidant compounds called flavonoids and phenolic acids.
Researchers Gow-Chin Yen and Chin-Lin Hsu point out that large amounts of those compounds occur in fruits, vegetables, nuts and plant-based beverages such as coffee, tea, and wine. Scientists long have known that flavonoids and phenolic acids have beneficial health effects in reducing the risk of heart attacks, cancer, obesity, and other disorders. However, there has been uncertainty about exactly how these compounds affect adipocytes, or fat cells.
The researchers studied how 15 phenolic acids and six flavonoids affected fat cells in laboratory cultures of mouse cells. Their results showed that fat cells exposed to certain antioxidants had lower levels of an enzyme that forms triglycerides and accumulated lower levels of triglycerides — fatty materials which at high levels increase the risk of heart disease.
The findings suggest that these compounds could be effective in improving the symptoms of metabolic syndrome, a cluster of symptoms like obesity and high blood sugar that increase the risk of heart disease, the researchers said.
The study “Effects of Flavonoids and Phenolic Acids on the Inhibition of Adipogenesis in 3T3-L1 Adipocytes” was published Oct. 17 in the Journal of Agricultural and Food Chemistry.
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